Effects of Using Ammonia as a Primary Fuel on Engine Performance and Emission in Ammonia/Biodiesel Dual-Fuel Ci Engine

Ammonia can be used as a carbon-free alternative fuel for Internal Combustion Engines (ICE). It has an excellent potential to replace fossil fuels. This study aims to show the possibility of utilizing ammonia as a primary fuel in a dual-fuel diesel engine. Hence, a single-cylinder diesel engine was retrofitted to inject ammonia into the intake manifold, and then a pilot dose of biodiesel is injected to initiate the combustion of the premixed ammonia-air mixture. Effects of various ammonia load contributions with a constant load of biodiesel on engine performance and emissions were investigated. Furthermore, a one-dimensional model has been developed to analyze the combustion of ammonia and biodiesel. Results reveal that 59% of biodiesel input energy can replace by ammonia and achieve the same brake thermal efficiency. Moreover, Increasing ammonia load contribution reduced CO2, CO, and HC emissions significantly. However, it increased NO emission. It was found that increasing ammonia input energy delayed the start of combustion due to the low in-cylinder temperature and high resistance to autoignition. However, the combustion duration decreased 52 CAD compared to only biodiesel operation, since most of the heat was released during the premixed combustion phase